1. Field of the Invention
The present invention relates in general to both an oxygen generating agent and an oxygen generating catalyst used for oxygen supply and, more particularly, to both a granulated oxygen generating agent of the sodium carbonate peroxyhydrate suitable for use in continuous generation of a desired amount of oxygen for a long time and an oxygen generating catalyst for reaction with the above oxygen generating agent while free controlling both the generation amount of oxygen and the oxygen generating reaction time.
2. Description of the Prior Art
It is well known to those skilled in the art that the oxygen can be generated by adding water to sodium carbonate peroxyhydrate 2Na.sub.2 CO.sub.3.3H.sub.2 O.sub.2, which peroxyhydrate is used as an oxygen generating source, in the presence of catalyst.
In order to not only prevent abrupt generation of large amount of oxygen but also assure stable and constant supply of a predetermined amount of oxygen for a long time, Japanese patent Laid-open Publication No. Sho. 60-44242 discloses a method for solidifying the sodium carbonate peroxyhydrate using varieties of arabic pastes having different concentrations.
Japanese Patent No. Hesei. 3-53907 discloses an oxygen generating agent. This oxygen generating agent is produced by coating a water-soluble layer such as a polyethylene glycol layer on the sodium carbonate peroxyhydrate and forming a micro capsule of the sodium carbonate peroxyhydrate. The sodium carbonate peroxyhydrate micro capsule is, thereafter, applied with catalase particles or rheonate on its water-soluble coating. The above oxygen generating agent is preferably used for continuous supply of oxygen for a week or a month.
However, the oxygen generating agent disclosed in Japanese Patent No. Hesei. 3-53907, while continuously generating the oxygen for a long time, that is, for a week or a month, nevertheless has a problem in that its production process should comprise many steps, thus increasing the cost of the result product. Furthermore, this oxygen generating agent is apt to naturally absorb moisture. Such moisture absorption causes deterioration of both quality and preservation of the agent.
In order to produce oxygen generating catalysts, the above Japanese patent Laid-open Publication No. Sho. 60-44242 also discloses a method for solidifying a metal salt, used as an oxygen generating catalyst, using varieties of arabic pastes having different concentrations. On the other hand, the present inventors discloses, in Japanese Patent No. Hesei. 3-53907, the oxygen generating agent which is produced by coating the water-soluble layer, such as the polyethylene glycol layer, on the sodium carbonate peroxyhydrate and forming the micro capsule of the sodium carbonate peroxyhydrate and, thereafter, applying the micro capsule with catalase particles or rheonate on its water-soluble coating.
The oxygen generating reaction according to the above method disclosed in Japanese Patent Laid-open Publication No. Sho. 60-44242 is continued for about 20-30 mins., so that this method can be effectively used for first aid. However, since this method generates the oxygen for such a relatively short time, it can not be used in certain situations such as for transportation of marine products requiring continuous oxygen supply for at least one hour. Furthermore, in the above method, a metal salt such as manganese dioxide or manganese sulfate should be used as the oxygen generating catalyst, so that the reaction sewage inevitably includes environmental contaminants. The contaminant-laden sewage will kill the marine products during the transportation of marine products.
Meanwhile, the method of Japanese Patent No. Hesei. 3-53907 wherein the oxygen generating agent is produced by forming the micro capsule of the sodium carbonate peroxyhydrate at the same time of applying the catalase particles or rheonate on the water-soluble coating of the micro capsule, requires a complex production process, thus increasing its cost. This oxygen generating agent is also apt to naturally absorb moisture, which moisture will cause deterioration of quality and preservation of the oxygen generating agent.